mise: Improper Neutralization of Special Elements used in an OS Command
CVE-2026-103929 is a high-severity improper neutralization of special elements used in an OS command vulnerability in mise from Jdx, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected mise versions: < 2026.7.14. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.26% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of mise you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by CNA (github.com).
Official description
mise manages dev tools like node, python, cmake, and terraform. Prior to 2026.7.14, in the default non-safe mode, mise loads .mise.toml [settings] from an untrusted local project before trust approval and strip_local_only_settings removes only fields marked global_only. The unix_default_file_shell_args, unix_default_inline_shell_args, windows_default_file_shell_args, and windows_default_inline_shell_args settings were not marked global_only, allowing a repository to replace the default interpreter arguments used by trusted tasks that have no explicit shell, postinstall directives, template exec operations, or hooks that fall back to the default shell. When mise appends the trusted command after the attacker-controlled interpreter arguments, the attacker-selected command can execute first with the developer account's privileges even though the local configuration was never trusted. The separate path-sanitization hardening note in the advisory is outside this vulnerability. This issue is fixed in version 2026.7.14.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in an OS Command
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.
How developers prevent this class of flaw
- If at all possible, use library calls rather than external processes to recreate the desired functionality.
- For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Improper Neutralization of Special Elements used in an OS Command vulnerabilities (CWE-78)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in mise
- 8.6 High severity
- 9.6 Critical severity
- 7.8 High severity
Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities
- 7.2 High severity
- 8.4 High severity
- 8.8 High severity
- 7.8 High severity
- 8.8 High severity
- 9.8 Critical severity
Spotted an error? Tell us.